894 ESSENTIAL OILS. 



per cent of oxygen, and considered as a hydrate of lemon oil, 

 3C 10 H 8 + 2HO. But MM. Soubeiran and Capitaine find it to 

 be a mixture of 2 or more oils, which differ in volatility, but 

 could not be completely separated, with the proportion of 

 oxygen varying from 3.37 to 16. 14 per cent. By the action of 

 anhydrous phosphoric acid upon this essence, an oil is obtained 

 which has the same composition as oil of lemons, or is of the 

 C 5 H 4 type. By the action of phosphoric acid on the impure oil 

 a peculiar acid was also produced (named phospho-bergamic 

 acid), which forms soluble salts with lime and oxide of 

 lead. 



Oil of doves, from the undeveloped flower-buds of the Caryo- 

 phyllus aromaticus. It is colourless or yellowish, becoming 

 brown in air, of a strong odour and burning taste ; its density is 

 1.061. Clove oil consists of two different oils, one light, of the 

 C 5 H 4 type, the other heavy, of density 1.079, and boiling point 

 469. 4 (243. centig.) which forms crystalline compounds with 

 bases, and is named caryophyllic acid. The two oils are sepa- 

 rated by distillation of the crude oil with a solution of potash, 

 by which the heavy or proper clove oil is retained in combi- 

 nation, and may afterwards be liberated by means of sulphuric 

 acid. Alcohol also extracts from cloves a solid substance, cary- 

 ophylline, of which the formula, according to both Dumas and 

 Ettling, is C 20 H 16 O 2 . The distilled water . of cloves deposits 

 another substance in yellowish pearly scales, which has been 

 named eugenine by Bonastre. 



Oil of anise, from Pimpinella anisum, is yellowish or colour- 

 less, of density 0.9857. It contains so much stearopten that it 

 is solid at the usual temperature. 



The stearopten obtained by pressure of the oil cooled to 32, 

 crystallizes in colourless plates, fuses about 64, and boils at 

 431. 6. Its composition, according to the latest determination 

 of M. Cahours, is C 20 H 12 O 2 . With chlorine it appears to form 

 two semifluid compounds of a viscid consistence, C 20 H 9 C1 3 O 2 , 

 and C 20 H 7i Cl 4i O 2 . With bromine the action is more definite, 

 and a crystalline compound is formed, bromanisal, C 20 H 9 Br 3 O 2 . 

 If 1 4 parts of sulphuric acid are digested with 1 part of the 

 concrete essence, the latter is entirely converted into a substance 

 of a resinous nature, which when purified from sulphuric acid 

 by distillation, is termed aniso'ine, by Cahours. It is a per- 



